Attention:
Due to more than one person being confused by the term 'followed by' & just to be clear you type the password and follow it immediately with the code all as one in the “password” field. You don’t get a second place to enter the code, it tailgates the actual password.
First you must close the dialog telling you to do this, to get back to the password entry field.
Then, if your password is pa55word and your verification code is 123456, then in the password field you must enter pa55word123456 all in one string at one time.
According to this Apple Support page, the issue is two-factor authentication with older devices/iOS.
What if I use two-factor authentication on a device running older software?
If you use two-factor authentication with devices running older OS versions, you might be asked to add your six-digit verification code to the end of your password when signing in.
Answer from bsf on Stack ExchangeGet your verification code from a trusted device running iOS 9 and later or OS X El Capitan and later, or have it sent to your trusted phone number. Then type your password followed by the six-digit verification code directly into the password field without any spaces between the password and the verification code.
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Attention:
Due to more than one person being confused by the term 'followed by' & just to be clear you type the password and follow it immediately with the code all as one in the “password” field. You don’t get a second place to enter the code, it tailgates the actual password.
First you must close the dialog telling you to do this, to get back to the password entry field.
Then, if your password is pa55word and your verification code is 123456, then in the password field you must enter pa55word123456 all in one string at one time.
According to this Apple Support page, the issue is two-factor authentication with older devices/iOS.
What if I use two-factor authentication on a device running older software?
If you use two-factor authentication with devices running older OS versions, you might be asked to add your six-digit verification code to the end of your password when signing in.
Get your verification code from a trusted device running iOS 9 and later or OS X El Capitan and later, or have it sent to your trusted phone number. Then type your password followed by the six-digit verification code directly into the password field without any spaces between the password and the verification code.
It is more than that. It is much worse:
The code is received with a space inside as XXX XXX and Apple expects users to enter it without space as XXXXXX. Why confuse people that way?
And even more:
Does not work any more on some divices like iPhone 4. Such phone has iOS 7.1.2 (11D257) and cannot be updated-upgraded. It seems that
"To use iCloud you need at least iOS 9 on iPhone 4, iPod touch (5th generation), iPad or iPad mini; or at least OS X El Capitan 10.11 on a Mac" https://support.apple.com/en-us/118308
If that is what happens, why Apple misleads users not indicating that and showing instead prompts to enter codes, etc? I have lost several days on this. FRUSTRATING!!! Apple, please, please, please, FIX this. Either allow iCloud on iPhone 4 or clearly report that to the user trying to use it or the App Store on such devices. Thanks!
Trying to sign in an old ipod and its making me do the apple id verification code. So right when i type in my password my ipad gets a message saying someone is trying to login do you want to allow and i hit yet. Then it gives me a verification code and says. "Type your password followed by this code into the password field on your device. Then it gives me a number like 484 862. I type this in after my password and nothing happens. Do I use spacing or what because ive tried everything i can think of and nothing works. This is ridiculous